The first treatise in MS 169 is seemingly a uniquely extant text (noted in Thorndike and Kibre's Catalogue of Incipits. In the late 15th-century hand of Robert of Sherburn, it is entitled Expositio cum questionibus super textu Rasis in 9o Almansoris. The text itself is contained on ff. 3r-37r, and on ff. 41-44 there is an index to the text. The treatise seems to be questions, or a form of commentary, on the ninth book of medicine by the 10th-century Arabic physician and scholar, Abū Bakr Muḥammad ibn Zakarīyā’ al-Rāzī (known as Rasis or Rhazes in the Latin west).
Rasis was (and is) best known in medieval Europe for his work, 'Book of Medicine for Mansur', written in the early 10th century for an Iranian prince. The text contained nine chapters, or short books. Translated into Latin in the late 12th century by Gerard of Cremona, the work became known as 'Liber ad Almansorem'. The ninth book of this was especially popular and widely circulated on its own, becoming known distinctly as the 'Liber nonus ad Almansorem'. It is on this ninth section of the translation of Rasis's work that the first treatise in MS 169 comments on.
The treatise begins on f. 3r with the words Queritur utrum cibus obvians membris reducat... It ends on f. 37r with: plus semper hujus [?] calefacere et finit feliciter in die sancte margarete hora decima a.d. 1481 per manum magistri roberti sherburnie.
On ff. 41r-44r, following the text (and separated by three folios of another text) there is a Tabula to this first treatise in MS 169.
This text is by the 15th-century hand of the scribe, Robert of Sherburn.